mysql---基本操作_MySQL
早打算写些关于数据库操作方面的知识了，现在终于完成了第一篇，以下记录了关于mysql操作方面的基础知识
在window下，启动、停止mysql服务
启动mysql数据库
net start mysql
停止mysql数据库
net stop mysql
重新启动mysql数据库
net restart mysql
命令行形式，mysql基本命令的使用
1、命令的取消
c
2、退出mysql窗口
exit;或quit;或ctrl c
3、查看数据库版本号
select version();
4、显示当前存在的数据库
show databases;
5、选择test数据库
use test;
6、查看选择的数据库
select database();
7、设置数据库中文编码
set names utf8;
8、创建一个test数据库
create database test
9、创建一张mtest表
create table mtest(
id tinyint(2) unsigned not null auto_increment,
name varchar(20),
sex char(1),
email varchar(50),
birth datetime,
primary key (id)
);
10、向mtest表中插入一条数据
insert into mtest(`name`,`sex`,`email`,`birth`) values ('zhangsan','1','zhangsan@163.com',now());
11、查询mtest表中name为张三的信息
select * from mtest where name='zhangsan';
12、按照id号降序输出
select * from mtest order by id desc;
13、显示第11至20条数据信息
select * from mtest id limit 10,10;
一.首先配置jdk环境变量：
1.配置jdk的变量名，jdk的目录
2.配置jdk的path（路径bin;）和mysql的path路径，指定bin目录（cmd下任意目录下可以访问mysql）
3.指定ClassPath
或者看以下配置：
1.环境变量的配置
我的电脑---属性-----高级------环境变量。
方法1 ：固定配置：
A.
新建java_home： 找jdk目录。 例如新建 D:Program FilesJavajdk（ 配置java_home以后就不怕换别的盘符了。直接修改java_home,不用修改path了）
B.
编辑path： 找bin路径。 在路径后面添加bin的路径 %java_home%bin或者在没有配置java_home的情况下直接例如D:Program FilesJavajdkbin（查找顺序，先在本目录查找，然后再在path路径查找。）
C.
CLASSpath 新建 确定找生成的.class目录。进入.java的目录后，如果在classpath中设置了.classpath的路径，就可以在dos环境下任意的目录下找到.class文件
二：
- C:WindowsSystem32>mysql -hlocalhost -u用户名 -p密码 //输入 用户名和密码，登录数据库
- mysql> show databases;//查看数据库
- mysql> use 数据库名;//进入数据库
- mysql> show tables;//查看表
- mysql> desc 表;//查看表结构
三.
创建数据库：
create database 数据库名；
mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">create</span> <span style="COLOR: rgb(0,0,255)">database</span><span style="COLOR: rgb(0,0,0)"> sql_db; mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">use</span><span style="COLOR: rgb(0,0,0)"> sql_db;</span><span style="COLOR: rgb(128,128,128)"><br></span>
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删除数据库：
drop database 数据库名；
在数据中（标准语句）
创建表：
create table 货物信息 (名称 类型 null|not null 主键或者唯一键,……);//包含了创建表时就建立约束语法。
mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">create</span> <span style="COLOR: rgb(0,0,255)">table</span> student (id <span style="COLOR: rgb(0,0,255)">int</span> <span style="COLOR: rgb(128,128,128)">not</span> <span style="COLOR: rgb(0,0,255)">null</span> auto_increment <span style="COLOR: rgb(0,0,255)">primary</span> <span style="COLOR: rgb(0,0,255)">key</span>,name <span style="COLOR: rgb(0,0,255)">varchar</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">10</span>),cid <span style="COLOR: rgb(0,0,255)">int</span><span style="COLOR: rgb(0,0,0)">); mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">create</span> <span style="COLOR: rgb(0,0,255)">table</span> class (id <span style="COLOR: rgb(0,0,255)">int</span> <span style="COLOR: rgb(128,128,128)">not</span> <span style="COLOR: rgb(0,0,255)">null</span> auto_increment <span style="COLOR: rgb(0,0,255)">primary</span> <span style="COLOR: rgb(0,0,255)">key</span>,name <span style="COLOR: rgb(0,0,255)">varchar</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">10</span>));
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删除表：
drop table 表名；
修改表 ：
alter table 表名
增加列： add column 列名 数据类型（长度）null or not null 主键or唯一键；ADD [COLUMN] column_definition [FIRST | AFTER col_name ]
mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">alter</span> <span style="COLOR: rgb(0,0,255)">table</span> student <span style="COLOR: rgb(0,0,255)">add</span> <span style="COLOR: rgb(0,0,255)">column</span> age <span style="COLOR: rgb(0,0,255)">int</span> ;
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删除列： drop column 列名；DROP [COLUMN] col_name
mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">alter</span> <span style="COLOR: rgb(0,0,255)">table</span> student <span style="COLOR: rgb(0,0,255)">drop</span> <span style="COLOR: rgb(0,0,255)">column</span> age;
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更改列： change column 原列名 新列名 数据类型（长度）； CHANGE [COLUMN] old_col_name column_definition [FIRST|AFTER col_name]
modify column 列名 数据类型（长度）；MODIFY [COLUMN] column_definition [FIRST | AFTER col_name]
column_definition:
col_name data_type [NOT NULL | NULL] [DEFAULT default_value] [AUTO_INCREMENT] [UNIQUE [KEY] | [PRIMARY] KEY] [COMMENT 'string'] [reference_definition]
mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">desc</span><span style="COLOR: rgb(0,0,0)"> class; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-----+-------------+------+-----+---------+-------+</span> <span style="COLOR: rgb(128,128,128)">|</span> Field <span style="COLOR: rgb(128,128,128)">|</span> Type <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">Null</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">Key</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">Default</span> <span style="COLOR: rgb(128,128,128)">|</span> Extra <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-----+-------------+------+-----+---------+-------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">int</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span>) <span style="COLOR: rgb(128,128,128)">|</span> NO <span style="COLOR: rgb(128,128,128)">|</span> PRI <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">varchar</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">10</span>) <span style="COLOR: rgb(128,128,128)">|</span> YES <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-----+-------------+------+-----+---------+-------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> rows <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span><span style="COLOR: rgb(0,0,0)"> sec) 如果想去除自动增长，则 先删除主键，再修改。 mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">alter</span> <span style="COLOR: rgb(0,0,255)">table</span> class <span style="COLOR: rgb(0,0,255)">drop</span> <span style="COLOR: rgb(0,0,255)">primary</span> <span style="COLOR: rgb(0,0,255)">key</span><span style="COLOR: rgb(0,0,0)">; mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">desc</span><span style="COLOR: rgb(0,0,0)"> class; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-----+-------------+------+-----+---------+-------+</span> <span style="COLOR: rgb(128,128,128)">|</span> Field <span style="COLOR: rgb(128,128,128)">|</span> Type <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">Null</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">Key</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">Default</span> <span style="COLOR: rgb(128,128,128)">|</span> Extra <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-----+-------------+------+-----+---------+-------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">int</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span>) <span style="COLOR: rgb(128,128,128)">|</span> NO <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">varchar</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">10</span>) <span style="COLOR: rgb(128,128,128)">|</span> YES <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-----+-------------+------+-----+---------+-------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> rows <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.01</span><span style="COLOR: rgb(0,0,0)"> sec) mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">alter</span> <span style="COLOR: rgb(0,0,255)">table</span> class modify <span style="COLOR: rgb(0,0,255)">column</span> id <span style="COLOR: rgb(0,0,255)">int</span> <span style="COLOR: rgb(0,0,255)">null</span>;
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如果没有在原始没有给列添加为主键，可以 添加和删除约束的方法。
alter table 表名 add primary key(id);或者更改列 mysql> alter table 表 change id id int primary key;
例子：
mysql> alter table 表名 add primary key(id);
删除主键：
alter table 表名 drop primary key();
例子：
mysql> alter table emp drop primary key;
四.
表数据中的增删改查
1.向表中添加数据：（全部插入）insert into 表名 valus('','',……,'');
（部分插入）insert into 表名(列x，列y，……，列z) valus('','',……,'');
student中 （自动增长，赋予0和null 并不影响自动增长性。）：
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mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">insert</span> <span style="COLOR: rgb(0,0,255)">into</span> student <span style="COLOR: rgb(0,0,255)">values</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span>,<span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(255,0,0)">s1</span><span style="COLOR: rgb(255,0,0)">'</span>,<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span><span style="COLOR: rgb(0,0,0)">); mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">insert</span> <span style="COLOR: rgb(0,0,255)">into</span> student <span style="COLOR: rgb(0,0,255)">values</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span>,<span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(255,0,0)">s2</span><span style="COLOR: rgb(255,0,0)">'</span>,<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span><span style="COLOR: rgb(0,0,0)">); mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">insert</span> <span style="COLOR: rgb(0,0,255)">into</span> student <span style="COLOR: rgb(0,0,255)">values</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span>,<span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(255,0,0)">s3</span><span style="COLOR: rgb(255,0,0)">'</span>,<span style="COLOR: rgb(0,0,255)">null</span><span style="COLOR: rgb(0,0,0)">);<br><span style="COLOR: rgb(255,255,255); BACKGROUND-COLOR: rgb(128,0,0)">mysql> insert into student values(0,'s3',3);//将在2中被删除</span> mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">insert</span> <span style="COLOR: rgb(0,0,255)">into</span> student <span style="COLOR: rgb(0,0,255)">values</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span>,<span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(255,0,0)">s4</span><span style="COLOR: rgb(255,0,0)">'</span>,<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span><span style="COLOR: rgb(0,0,0)">); mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">insert</span> <span style="COLOR: rgb(0,0,255)">into</span> student(id,name) <span style="COLOR: rgb(0,0,255)">values</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span>,<span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(255,0,0)">s5</span><span style="COLOR: rgb(255,0,0)">'</span>);<br><br>
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class中：
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mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">insert</span> <span style="COLOR: rgb(0,0,255)">into</span> class(id,name) <span style="COLOR: rgb(0,0,255)">values</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span>,<span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(255,0,0)">c1</span><span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(0,0,0)">); mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">insert</span> <span style="COLOR: rgb(0,0,255)">into</span> class(id,name) <span style="COLOR: rgb(0,0,255)">values</span>(<span style="COLOR: rgb(0,0,255)">null</span>,<span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(255,0,0)">c2</span><span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(0,0,0)">); //指定id为4 mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">insert</span> <span style="COLOR: rgb(0,0,255)">into</span> class(id,name) <span style="COLOR: rgb(0,0,255)">values</span>(2,<span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(255,0,0)">c3</span><span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(0,0,0)">); mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span><span style="COLOR: rgb(0,0,0)"> class; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> c1 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> c2 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">4</span> <span style="COLOR: rgb(128,128,128)">|</span> c3 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+</span>
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2.向表中删除行数据：delect from 表名；（清空表）
delect from 表名 where [检索条件表达式]
mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">delete</span> <span style="COLOR: rgb(0,0,255)">from</span> student <span style="COLOR: rgb(0,0,255)">where</span> id<span style="COLOR: rgb(128,128,128)">=</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">4</span>;
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3.更改表中的数据：update 表名 set 列名='表达式' [from 另一表名] where [检索条件表达式];
mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">update</span> student <span style="COLOR: rgb(0,0,255)">set</span> name<span style="COLOR: rgb(128,128,128)">=</span><span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(255,0,0)">s11</span><span style="COLOR: rgb(255,0,0)">'</span> <span style="COLOR: rgb(0,0,255)">where</span> id<span style="COLOR: rgb(128,128,128)">=</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span>;
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4.查询表中的数据：select */表字段1，表字段2，……表字段n from 表名 【where 查询条件】；
mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span><span style="COLOR: rgb(0,0,0)"> student; mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span> student <span style="COLOR: rgb(0,0,255)">where</span> id<span style="COLOR: rgb(128,128,128)">=</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span><span style="COLOR: rgb(0,0,0)">; mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> id,name <span style="COLOR: rgb(0,0,255)">from</span><span style="COLOR: rgb(0,0,0)"> student; mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> id,name <span style="COLOR: rgb(0,0,255)">from</span> student <span style="COLOR: rgb(0,0,255)">where</span> id <span style="COLOR: rgb(128,128,128)">in</span>(<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span>,<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3，4</span>);<span style="COLOR: rgb(128,128,128)">//</span>in表示集合。
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特殊查询：
//增加一列<br>mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">alter</span> <span style="COLOR: rgb(0,0,255)">table</span> student <span style="COLOR: rgb(0,0,255)">add</span> <span style="COLOR: rgb(0,0,255)">column</span> createDate date;
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//查询是否增加<br>mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span><span style="COLOR: rgb(0,0,0)"> student; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> cid <span style="COLOR: rgb(128,128,128)">|</span> createDate <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> s11 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> s2 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> s3 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> <span style="COLOR: rgb(128,128,128)">|</span> s4 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">6</span> <span style="COLOR: rgb(128,128,128)">|</span> s5 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> rows <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span><span style="COLOR: rgb(0,0,0)"> sec) <br>//插入date类型格式的日期。 mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">update</span> student <span style="COLOR: rgb(0,0,255)">set</span> createDate<span style="COLOR: rgb(128,128,128)">=</span><span style="COLOR: rgb(255,0,0)">'</span><span style="COLOR: rgb(255,0,0)">2012-11-16</span><span style="COLOR: rgb(255,0,0)">'</span> <span style="COLOR: rgb(0,0,255)">where</span> id<span style="COLOR: rgb(128,128,128)">=</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span><span style="COLOR: rgb(0,0,0)">;//date时间类型 yyyy-mm-dd 格式 。createDate='2012-9-8'，必须这么写。 Query OK, </span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> row affected (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.02</span><span style="COLOR: rgb(0,0,0)"> sec) Rows matched: </span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> Changed: <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> Warnings: <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span><span style="COLOR: rgb(0,0,0)"> <br> mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span><span style="COLOR: rgb(0,0,0)"> student; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> cid <span style="COLOR: rgb(128,128,128)">|</span> createDate <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> s11 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> s2 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> s3 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2012</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">16</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> <span style="COLOR: rgb(128,128,128)">|</span> s4 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">6</span> <span style="COLOR: rgb(128,128,128)">|</span> s5 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> rows <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span><span style="COLOR: rgb(0,0,0)"> sec) <br>//插入当前日期</span><span style="COLOR: rgb(0,0,0)"> mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">update</span> student <span style="COLOR: rgb(0,0,255)">set</span> createDate<span style="COLOR: rgb(128,128,128)">=</span>now() <span style="COLOR: rgb(0,0,255)">where</span> id<span style="COLOR: rgb(128,128,128)">=</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span><span style="COLOR: rgb(0,0,0)">; Query OK, </span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> row affected (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span><span style="COLOR: rgb(0,0,0)"> sec) Rows matched: </span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> Changed: <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> Warnings: <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span><span style="COLOR: rgb(0,0,0)"> mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span><span style="COLOR: rgb(0,0,0)"> student; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> cid <span style="COLOR: rgb(128,128,128)">|</span> createDate <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> s11 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> s2 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> s3 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2012</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">16</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> <span style="COLOR: rgb(128,128,128)">|</span> s4 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2012</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">17</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">6</span> <span style="COLOR: rgb(128,128,128)">|</span> s5 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> rows <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span><span style="COLOR: rgb(0,0,0)"> sec) <br><br>统计查询(sum.avg,count)</span>
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<br>mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(255,0,255)">count</span>(<span style="COLOR: rgb(128,128,128)">*</span>) <span style="COLOR: rgb(0,0,255)">from</span> student <span style="COLOR: rgb(0,0,255)">where</span> id<span style="COLOR: rgb(128,128,128)">></span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span><span style="COLOR: rgb(0,0,0)">; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(255,0,255)">count</span>(<span style="COLOR: rgb(128,128,128)">*</span>) <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> row <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.03</span><span style="COLOR: rgb(0,0,0)"> sec) mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(255,0,255)">count</span>(name) <span style="COLOR: rgb(0,0,255)">from</span> student <span style="COLOR: rgb(0,0,255)">where</span> id<span style="COLOR: rgb(128,128,128)">></span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span><span style="COLOR: rgb(0,0,0)">; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-----------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(255,0,255)">count</span>(name) <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-----------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-----------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> row <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span><span style="COLOR: rgb(0,0,0)"> sec) mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(255,0,255)">sum</span>(id) <span style="COLOR: rgb(0,0,255)">from</span><span style="COLOR: rgb(0,0,0)"> student; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(255,0,255)">sum</span>(id) <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">17</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> row <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.03</span> sec)<br><br>
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<span style="COLOR: rgb(0,0,0)">查询最大的id mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(255,0,255)">max</span>(id) <span style="COLOR: rgb(0,0,255)">from</span><span style="COLOR: rgb(0,0,0)"> student; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(255,0,255)">max</span>(id) <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">6</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> row <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span><span style="COLOR: rgb(0,0,0)"> sec) 查询最小的id mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(255,0,255)">min</span>(id) <span style="COLOR: rgb(0,0,255)">from</span><span style="COLOR: rgb(0,0,0)"> student; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(255,0,255)">min</span>(id) <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> row <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.07</span> sec)
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分页查询（mysql专用）：
page表示要查询的页码（1开始），pagesize表示一页显示多少条记录
begin=（page-1）*pagesize；表示查询页开始的行号。 注意：行记录是从0开始
<br>mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span> 表 limit <span style="COLOR: rgb(0,0,255)">begin</span><span style="COLOR: rgb(0,0,0)">,pagesize; mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span> student limit <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span>,<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span><span style="COLOR: rgb(0,0,0)">; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> cid <span style="COLOR: rgb(128,128,128)">|</span> createDate <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> s11 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> s2 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> s3 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2012</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">16</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> rows <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.03</span><span style="COLOR: rgb(0,0,0)"> sec) mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span> student limit <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span>,<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span><span style="COLOR: rgb(0,0,0)">; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> cid <span style="COLOR: rgb(128,128,128)">|</span> createDate <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> <span style="COLOR: rgb(128,128,128)">|</span> s4 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2012</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">17</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">6</span> <span style="COLOR: rgb(128,128,128)">|</span> s5 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span>
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查询 id<span style="COLOR: rgb(128,128,128)"><span style="COLOR: rgb(0,0,0)">3的，再以分页显示 mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span> student <span style="COLOR: rgb(0,0,255)">where</span> id<span style="COLOR: rgb(128,128,128)"><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> limit <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span>,<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span><span style="COLOR: rgb(0,0,0)">; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> cid <span style="COLOR: rgb(128,128,128)">|</span> createDate <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> s11 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> row <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span><span style="COLOR: rgb(0,0,0)"> sec) </span><span style="COLOR: rgb(128,128,128)">//</span><span style="COLOR: rgb(0,0,0)">降序 mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span> student <span style="COLOR: rgb(0,0,255)">order</span> <span style="COLOR: rgb(0,0,255)">by</span> id <span style="COLOR: rgb(0,0,255)">desc</span><span style="COLOR: rgb(0,0,0)">; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> cid <span style="COLOR: rgb(128,128,128)">|</span> createDate <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">6</span> <span style="COLOR: rgb(128,128,128)">|</span> s5 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> <span style="COLOR: rgb(128,128,128)">|</span> s4 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2012</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">17</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> s3 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2012</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">16</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> s2 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> s11 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> rows <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span><span style="COLOR: rgb(0,0,0)"> sec) 升序（默认） mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span> student <span style="COLOR: rgb(0,0,255)">order</span> <span style="COLOR: rgb(0,0,255)">by</span> id <span style="COLOR: rgb(0,0,255)">asc</span><span style="COLOR: rgb(0,0,0)">; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> cid <span style="COLOR: rgb(128,128,128)">|</span> createDate <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> s11 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> s2 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> s3 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2012</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">16</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> <span style="COLOR: rgb(128,128,128)">|</span> s4 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2012</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">17</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">6</span> <span style="COLOR: rgb(128,128,128)">|</span> s5 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> rows <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span><span style="COLOR: rgb(0,0,0)"> sec) 查询id</span><span style="COLOR: rgb(128,128,128)">></span><span style="COLOR: rgb(0,0,0)">2的，降序排列，分页查询 mysql</span><span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span> student <span style="COLOR: rgb(0,0,255)">where</span> id <span style="COLOR: rgb(128,128,128)">></span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> <span style="COLOR: rgb(0,0,255)">order</span> <span style="COLOR: rgb(0,0,255)">by</span> id <span style="COLOR: rgb(0,0,255)">desc</span> limit <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0</span>,<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span><span style="COLOR: rgb(0,0,0)">; </span><span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> cid <span style="COLOR: rgb(128,128,128)">|</span> createDate <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">6</span> <span style="COLOR: rgb(128,128,128)">|</span> s5 <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">5</span> <span style="COLOR: rgb(128,128,128)">|</span> s4 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">3</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2012</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">11</span><span style="COLOR: rgb(128,128,128)">-</span><span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">17</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)">+</span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">--+------+------+------------+</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">2</span> rows <span style="COLOR: rgb(128,128,128)">in</span> <span style="COLOR: rgb(0,0,255)">set</span> (<span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">0.00</span> sec)</span></span>
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链接查询（针对2个表）：
3.关联查询：
mysql> select * from 表1,表2 where 表1.列1=表2.列2
mysql<span style="COLOR: rgb(128,128,128)">></span> <span style="COLOR: rgb(0,0,255)">select</span> <span style="COLOR: rgb(128,128,128)">*</span> <span style="COLOR: rgb(0,0,255)">from</span> student s,class c <span style="COLOR: rgb(0,0,255)">where</span> s.cid<span style="COLOR: rgb(128,128,128)">=</span><span style="COLOR: rgb(0,0,0)">c.id; </span><span style="COLOR: rgb(128,128,128)"> </span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-- ------ ------ ------------ ------ ------ </span> <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> cid <span style="COLOR: rgb(128,128,128)">|</span> createDate <span style="COLOR: rgb(128,128,128)">|</span> id <span style="COLOR: rgb(128,128,128)">|</span> name <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(128,128,128)"> </span><span style="COLOR: rgb(0,128,128)">--</span><span style="COLOR: rgb(0,128,128)">-- ------ ------ ------------ ------ ------ </span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> s11 <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="COLOR: rgb(0,0,255)">NULL</span> <span style="COLOR: rgb(128,128,128)">|</span> <span style="FONT-WEIGHT: bold; COLOR: rgb(128,0,0)">1</span> <span style="COLOR: rgb(128,128,128)">|</span> c1 <span style="COLOR"></span>
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热门话题
说明InnoDB全文搜索功能。
Apr 02, 2025 pm 06:09 PM
InnoDB的全文搜索功能非常强大，能够显着提高数据库查询效率和处理大量文本数据的能力。 1）InnoDB通过倒排索引实现全文搜索，支持基本和高级搜索查询。 2）使用MATCH和AGAINST关键字进行搜索，支持布尔模式和短语搜索。 3）优化方法包括使用分词技术、定期重建索引和调整缓存大小，以提升性能和准确性。
如何使用Alter Table语句在MySQL中更改表？
Mar 19, 2025 pm 03:51 PM
本文讨论了使用MySQL的Alter Table语句修改表，包括添加/删除列，重命名表/列以及更改列数据类型。
与MySQL中使用索引相比，全表扫描何时可以更快？
Apr 09, 2025 am 12:05 AM
全表扫描在MySQL中可能比使用索引更快，具体情况包括：1)数据量较小时；2)查询返回大量数据时；3)索引列不具备高选择性时；4)复杂查询时。通过分析查询计划、优化索引、避免过度索引和定期维护表，可以在实际应用中做出最优选择。
可以在 Windows 7 上安装 mysql 吗
Apr 08, 2025 pm 03:21 PM
是的，可以在 Windows 7 上安装 MySQL，虽然微软已停止支持 Windows 7，但 MySQL 仍兼容它。不过，安装过程中需要注意以下几点：下载适用于 Windows 的 MySQL 安装程序。选择合适的 MySQL 版本（社区版或企业版）。安装过程中选择适当的安装目录和字符集。设置 root 用户密码，并妥善保管。连接数据库进行测试。注意 Windows 7 上的兼容性问题和安全性问题，建议升级到受支持的操作系统。
InnoDB中的聚类索引和非簇索引（次级索引）之间的差异。
Apr 02, 2025 pm 06:25 PM
聚集索引和非聚集索引的区别在于：1.聚集索引将数据行存储在索引结构中，适合按主键查询和范围查询。2.非聚集索引存储索引键值和数据行的指针，适用于非主键列查询。
哪些流行的MySQL GUI工具（例如MySQL Workbench，PhpMyAdmin）是什么？
Mar 21, 2025 pm 06:28 PM
文章讨论了流行的MySQL GUI工具，例如MySQL Workbench和PhpMyAdmin，比较了它们对初学者和高级用户的功能和适合性。[159个字符]
如何使用Drop Table语句将表放入MySQL中？
Mar 19, 2025 pm 03:52 PM
本文讨论了使用Drop Table语句在MySQL中放下表，并强调了预防措施和风险。它强调，没有备份，该动作是不可逆转的，详细介绍了恢复方法和潜在的生产环境危害。
